"The Fed might be thinking of monetary tapering but, for us, the only tapering is of our growth forecasts," warned Stephen King, HSBC's chief economist, and Madhur Jha, HSBC's global economist, in their third quarter global outlook.

HSBC cut its forecast for world growth to 2.0 percent in 2013, down from an earlier prediction of 2.2 percent. It also downgraded its 2014 outlook to 2.6 percent.

In a blow to those hopeful that emerging markets can propel global economic growth and boost anemic demand in the developed world, King and Jha said the downgrade was entirely due to concerns about the outlook in developing countries.

"The revisions this quarter are all centered on the emerging world: we have shaved 0.8 percentage points off our 2013 projection and 0.5 percentage points off our numbers for 2014," they wrote.

"While dominated by the reduction in our forecasts for China, the new numbers also reflect further sizable reductions in our projections for Brazil and India, among others. They are consistent with the idea that, even allowing for the emerging nations' obvious long-term growth advantages, there is no easy escape from deteriorating near-term economic fundamentals."

The HSBC report came a day after independent research firm Capital Economics said that Emerging Market (EM) growth had slowed to its weakest pace since the global financial crisis.

Average growth in emerging Asia, Latin America and emerging Europe slowed to 4 percent year-on-year in the first quarter of this year, according to data from Capital Economics and Thomson Datastream. In comparison, emerging markets grew by an average of 6.4 percent during the past decade.

King and Jha said that EMs had become "unusually dependent" on a combination of cheap U.S. money and strong Chinese growth, so much so that domestic reforms were often delayed.

"Balance of payments positions deteriorated and, in some cases, the split between growth and inflation worsened. For a while, none of this mattered: the hunt for yield engendered by quantitative easing allowed countries to carry on as if nothing had changed. With the removal of U.S. and Chinese support, however, some of these countries find themselves in a vulnerable position," they said.

In addition, King and Jha noted that Chinese's policy reorientation towards "quality" rather than quantity of growth was likely to be associated with lower short-term growth.

"While this new focus should prepare the foundations for a period of solid economic expansion over the medium-term, it has an obvious short-term cost: supply-side reforms are disruptive and thus likely to be associated with lower near-term growth," they said.

HSBC now forecasts that China will grow by 7.4 percent in both 2013 and 2014, below the central bank's target of 7.5 percent growth.

The more bearish outlook on China is shared by investors such as Jim O'Neill, the former chairman of Goldman Sachs Asset Management, who coined the moniker BRIC to describe the EMs which would drive world growth.

Although a strong advocate of the China growth story, O'Neill conceded this week that the country was unlikely to meet its central bank growth target in 2013.

"I mean 7.5 percent growth: that is the equivalent of the U.S. growing by four percent. It is huge. They are trying to change a lot of things at the same time and obviously as they creep forward through time, it probably gets harder to control," O'Neill told CNBC.

Joaquim Levy, former secretary of the treasury and CEO of Bradesco Asset, talked about the Brazilian economy, saying that despite some concerns, strong fundamentals remain.

Meanwhile, HSBC downgraded its outlook for Brazilian growth to 2.4 percent in 2013 and 3.0 percent in 2014. It said India would grow by 5.1 percent this year and 6.5 percent next, down from its previous prediction of 5.5 percent and 6.9 percent respectively.

However, some analysts fear the slowdown in emerging market growth could extend beyond the established BRIC markets. In April, the International Monetary Fund warned that the entire emerging Asia region risked falling into a "middle-income trap", where it would struggle to maintain growth, due to a lack of structural reforms.

"When the global cost of capital begins to rise, the structural flaws in many emerging markets will be exposed. As growth falters and debt loads rise, economies thus risk falling back into the middle income trap," HSBC's Frederic Neumann told CNBC, earlier this month.